Canadian Aviation Regulations · SOR/96-433
Unforeseen Operational Circumstances
When something beyond the operator's control happens within 60 minutes of, or during, a flight duty period, the pilot-in-command — and only the PIC — may extend or reduce the FDP or extend the rest period.
Applies to 703704705 · in force since December 12, 2020
An unforeseen operational circumstance (UOC) is defined in CARs 101.01 as “an event, such as unforecast adverse weather, or an equipment malfunction or air traffic control delay, that is beyond the control of an air operator or private operator.” To be usable here it must arise within 60 minutes of the start of, or during, the flight duty period (AC 700-047 § 4.70).
Something known more than 60 minutes before you report is not unforeseen and cannot be used to extend the FDP. Delays after the FDP ends (customs, inspections, airport issues) are recorded as duty time, not UOC.
What the PIC may do
If the pilot-in-command judges that a UOC could cause fatigue that may affect the safety of the flight, then after consulting all crew members on their fatigue, the PIC may (700.63(1)):
- reduce a flight crew member’s flight duty period;
- extend the FDP beyond the 700.28 or 700.60 maximum by:
| Crew | Maximum UOC extension | CARs |
|---|---|---|
| Single-pilot operation | 1 hour | 700.63(1)(b)(i) |
| Two-pilot (not augmented) | 2 hours | 700.63(1)(b)(ii) |
| Augmented, one flight in the FDP | 3 hours | 700.63(1)(b)(iii) |
| Augmented, two or three flights in the FDP | 2 hours | 700.63(1)(b)(iv) |
- or extend the rest period.
The authority is the PIC’s alone. The operator may set more restrictive guidance but cannot make the decision (AC 700-047 § 4.71).
After the extension
- If a further UOC arises after take-off on the final flight, the PIC may continue to the destination or an alternate (700.63(2)).
- The operator must extend the following rest period by at least the amount of the FDP extension (700.63(3); AC 700-047 § 4.73). Extend the FDP by 1.5 hours → the next rest period grows by 1.5 hours.
- At the end of the FDP the PIC must notify the operator of any change made under this section (700.63(4)).
Related
- PIC authority, explained
- Maximum Flight Duty Period (700.28)
- Split flight duty (700.50) — UOC re-planning credits a break at 50%
- Augmented crew (700.60)
Regulation text — CARs 700.63
Reproduced from the consolidated Canadian Aviation Regulations ( SOR/96-433) on the Justice Laws website. CARs 700.63
700.63 (1) If the pilot-in-command is of the opinion that an unforeseen operational circumstance that occurs within 60 minutes of the beginning of the flight duty period could lead to a level of fatigue that may adversely affect the safety of the flight, the pilot-in-command may, after consulting with all crew members on their level of fatigue,
- (a) reduce a flight crew member’s flight duty period;
- (b) extend a flight crew member’s flight duty period by the following number
of hours in excess of the maximum flight duty period set out in section 700.28
or subsection 700.60(1) by
- (i) one hour for a single-pilot operation,
- (ii) two hours, if the flight crew is not augmented,
- (iii) three hours, if the flight crew is augmented and there is one flight during the scheduled flight duty period, and
- (iv) two hours, if the flight crew is augmented and there are two or three flights during the scheduled flight duty period; or
- (c) extend a flight crew member’s rest period.
(2) If a further unforeseen operational circumstance arises after take-off on the final flight for which the maximum flight duty period was extended under subsection (1), the pilot-in-command may, despite that subsection, continue the flight to the destination aerodrome or to an alternate aerodrome.
(3) An air operator shall extend the rest period after a flight duty period is extended under this section by an amount of time that is at least equal to the extension of the flight duty period.
(4) At the end of a flight duty period, the pilot-in-command shall notify the air operator of any change to a flight duty period made under this section.
What changed in 2018
In plain language
The 2018 rules make explicit that the authority to extend a flight duty period for an unforeseen operational circumstance rests solely with the pilot-in-command, set fixed extension limits by crew type, and require the following rest period to grow by at least the extension.
Paraphrased from Advisory Circular 700-047 .